Over half a million Americans are living with the inflammatory gut disease known as Crohn’s disease. Previous research suggests stress as a factor, however, researchers have not been able to pinpoint the exact mechanism by which anxiety triggers inflammation. New research reveals the important role of stress hormones on immune cells, shedding light on the origin of Crohn’s disease.
Crohn’s disease is an autoimmune disorder that results in painful swelling of the intestines and occasional ulcers. Those with the disease usually have higher amounts of disease-causing microbes, such as the bacterium E. coli, according to earlier studies. Researchers from McMaster University examined populations of E.coli in the digestive tracts of mice to investigate the source behind the intestinal inflammation.
Stress, Immunity, and the Gut
Skin cells that line digestive organs are critical to gut immunity because they maintain structure, generate mucus, and prevent pathogens like harmful bacteria from damaging the gut. In healthy individuals, the skin cells are signaled by cells of the immune system to help guard against invading pathogens. However, in the case of Crohn’s disease, stress hormones disable the immune cells to protect digestive organs from harmful microbes, according to the results.
“The main takeaway is that psychological stress impedes the body’s ability to fight off gut bacteria that may be implicated in Crohn’s disease. Innate immunity is designed to protect us from microbes that do not belong in the gut, like harmful bacteria,” says senior author Brian Coombes, in a statement. Coombes is a professor and chair of biochemistry and biomedical sciences at McMaster.
E. coli and other harmful microbes dominate the gut, causing painful swelling.
“When our innate immune system functions properly, it prevents harmful bacteria from colonizing us, but when it breaks down, it leaves an opening for pathogens to colonize locations they normally cannot and cause illness,” Coombes adds.
When the stress hormones were eliminated, immune cells prevented pathogens from entering the gut, says Coombes. “The more we know about what triggers Crohn’s disease, the closer we come to new treatments and potentially even disease prevention,” adds Coombes.
It is possible that this research might lead to novel therapies for Crohn’s disease, however, Coombes stresses the need for further research. The next step is to test the effects of stress hormones on gut and immune functions in human clinical trials.
This study is published in Nature Communications.